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remarkable-linux/net/netfilter/nf_conntrack_proto_sctp.c
David S. Miller a01aa920b8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter updates for your net-next
tree. A large bunch of code cleanups, simplify the conntrack extension
codebase, get rid of the fake conntrack object, speed up netns by
selective synchronize_net() calls. More specifically, they are:

1) Check for ct->status bit instead of using nfct_nat() from IPVS and
   Netfilter codebase, patch from Florian Westphal.

2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao.

3) Simplify FTP IPVS helper module registration path, from Arushi Singhal.

4) Introduce nft_is_base_chain() helper function.

5) Enforce expectation limit from userspace conntrack helper,
   from Gao Feng.

6) Add nf_ct_remove_expect() helper function, from Gao Feng.

7) NAT mangle helper function return boolean, from Gao Feng.

8) ctnetlink_alloc_expect() should only work for conntrack with
   helpers, from Gao Feng.

9) Add nfnl_msg_type() helper function to nfnetlink to build the
   netlink message type.

10) Get rid of unnecessary cast on void, from simran singhal.

11) Use seq_puts()/seq_putc() instead of seq_printf() where possible,
    also from simran singhal.

12) Use list_prev_entry() from nf_tables, from simran signhal.

13) Remove unnecessary & on pointer function in the Netfilter and IPVS
    code.

14) Remove obsolete comment on set of rules per CPU in ip6_tables,
    no longer true. From Arushi Singhal.

15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng.

16) Remove unnecessary nested rcu_read_lock() in
    __nf_nat_decode_session(). Code running from hooks are already
    guaranteed to run under RCU read side.

17) Remove deadcode in nf_tables_getobj(), from Aaron Conole.

18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(),
    also from Aaron.

19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole.

20) Don't propagate NF_DROP error to userspace via ctnetlink in
    __nf_nat_alloc_null_binding() function, from Gao Feng.

21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks,
    from Gao Feng.

22) Kill the fake untracked conntrack objects, use ctinfo instead to
    annotate a conntrack object is untracked, from Florian Westphal.

23) Remove nf_ct_is_untracked(), now obsolete since we have no
    conntrack template anymore, from Florian.

24) Add event mask support to nft_ct, also from Florian.

25) Move nf_conn_help structure to
    include/net/netfilter/nf_conntrack_helper.h.

26) Add a fixed 32 bytes scratchpad area for conntrack helpers.
    Thus, we don't deal with variable conntrack extensions anymore.
    Make sure userspace conntrack helper doesn't go over that size.
    Remove variable size ct extension infrastructure now this code
    got no more clients. From Florian Westphal.

27) Restore offset and length of nf_ct_ext structure to 8 bytes now
    that wraparound is not possible any longer, also from Florian.

28) Allow to get rid of unassured flows under stress in conntrack,
    this applies to DCCP, SCTP and TCP protocols, from Florian.

29) Shrink size of nf_conntrack_ecache structure, from Florian.

30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker,
    from Gao Feng.

31) Register SYNPROXY hooks on demand, from Florian Westphal.

32) Use pernet hook whenever possible, instead of global hook
    registration, from Florian Westphal.

33) Pass hook structure to ebt_register_table() to consolidate some
    infrastructure code, from Florian Westphal.

34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the
    SYNPROXY code, to make sure device stats are not fooled, patch
    from Gao Feng.

35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we
    don't need anymore if we just select a fixed size instead of
    expensive runtime time calculation of this. From Florian.

36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(),
    from Florian.

37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from
    Florian.

38) Attach NAT extension on-demand from masquerade and pptp helper
    path, from Florian.

39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole.

40) Speed up netns by selective calls of synchronize_net(), from
    Florian Westphal.

41) Silence stack size warning gcc in 32-bit arch in snmp helper,
    from Florian.

42) Inconditionally call nf_ct_ext_destroy(), even if we have no
    extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from
    Liping Zhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-01 10:47:53 -04:00

857 lines
25 KiB
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/*
* Connection tracking protocol helper module for SCTP.
*
* Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
* Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
*
* SCTP is defined in RFC 2960. References to various sections in this code
* are to this RFC.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/netfilter.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/sctp.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <net/sctp/checksum.h>
#include <net/netfilter/nf_log.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_ecache.h>
/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
closely. They're more complex. --RR
And so for me for SCTP :D -Kiran */
static const char *const sctp_conntrack_names[] = {
"NONE",
"CLOSED",
"COOKIE_WAIT",
"COOKIE_ECHOED",
"ESTABLISHED",
"SHUTDOWN_SENT",
"SHUTDOWN_RECD",
"SHUTDOWN_ACK_SENT",
"HEARTBEAT_SENT",
"HEARTBEAT_ACKED",
};
#define SECS * HZ
#define MINS * 60 SECS
#define HOURS * 60 MINS
#define DAYS * 24 HOURS
static unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] __read_mostly = {
[SCTP_CONNTRACK_CLOSED] = 10 SECS,
[SCTP_CONNTRACK_COOKIE_WAIT] = 3 SECS,
[SCTP_CONNTRACK_COOKIE_ECHOED] = 3 SECS,
[SCTP_CONNTRACK_ESTABLISHED] = 5 DAYS,
[SCTP_CONNTRACK_SHUTDOWN_SENT] = 300 SECS / 1000,
[SCTP_CONNTRACK_SHUTDOWN_RECD] = 300 SECS / 1000,
[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = 3 SECS,
[SCTP_CONNTRACK_HEARTBEAT_SENT] = 30 SECS,
[SCTP_CONNTRACK_HEARTBEAT_ACKED] = 210 SECS,
};
#define sNO SCTP_CONNTRACK_NONE
#define sCL SCTP_CONNTRACK_CLOSED
#define sCW SCTP_CONNTRACK_COOKIE_WAIT
#define sCE SCTP_CONNTRACK_COOKIE_ECHOED
#define sES SCTP_CONNTRACK_ESTABLISHED
#define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
#define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
#define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
#define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
#define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
#define sIV SCTP_CONNTRACK_MAX
/*
These are the descriptions of the states:
NOTE: These state names are tantalizingly similar to the states of an
SCTP endpoint. But the interpretation of the states is a little different,
considering that these are the states of the connection and not of an end
point. Please note the subtleties. -Kiran
NONE - Nothing so far.
COOKIE WAIT - We have seen an INIT chunk in the original direction, or also
an INIT_ACK chunk in the reply direction.
COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction.
ESTABLISHED - We have seen a COOKIE_ACK in the reply direction.
SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction.
SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply directoin.
SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
to that of the SHUTDOWN chunk.
CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
the SHUTDOWN chunk. Connection is closed.
HEARTBEAT_SENT - We have seen a HEARTBEAT in a new flow.
HEARTBEAT_ACKED - We have seen a HEARTBEAT-ACK in the direction opposite to
that of the HEARTBEAT chunk. Secondary connection is
established.
*/
/* TODO
- I have assumed that the first INIT is in the original direction.
This messes things when an INIT comes in the reply direction in CLOSED
state.
- Check the error type in the reply dir before transitioning from
cookie echoed to closed.
- Sec 5.2.4 of RFC 2960
- Full Multi Homing support.
*/
/* SCTP conntrack state transitions */
static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
{
/* ORIGINAL */
/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
/* init */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
/* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
/* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
/* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
/* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
/* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
/* cookie_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
/* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
/* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
},
{
/* REPLY */
/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
/* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
/* init_ack */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
/* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
/* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
/* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
/* cookie_echo */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
/* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
/* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
/* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA}
}
};
static inline struct nf_sctp_net *sctp_pernet(struct net *net)
{
return &net->ct.nf_ct_proto.sctp;
}
static bool sctp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
struct net *net, struct nf_conntrack_tuple *tuple)
{
const struct sctphdr *hp;
struct sctphdr _hdr;
/* Actually only need first 4 bytes to get ports. */
hp = skb_header_pointer(skb, dataoff, 4, &_hdr);
if (hp == NULL)
return false;
tuple->src.u.sctp.port = hp->source;
tuple->dst.u.sctp.port = hp->dest;
return true;
}
static bool sctp_invert_tuple(struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_tuple *orig)
{
tuple->src.u.sctp.port = orig->dst.u.sctp.port;
tuple->dst.u.sctp.port = orig->src.u.sctp.port;
return true;
}
/* Print out the per-protocol part of the tuple. */
static void sctp_print_tuple(struct seq_file *s,
const struct nf_conntrack_tuple *tuple)
{
seq_printf(s, "sport=%hu dport=%hu ",
ntohs(tuple->src.u.sctp.port),
ntohs(tuple->dst.u.sctp.port));
}
/* Print out the private part of the conntrack. */
static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
{
seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
}
#define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \
for ((offset) = (dataoff) + sizeof(sctp_sctphdr_t), (count) = 0; \
(offset) < (skb)->len && \
((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \
(offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
/* Some validity checks to make sure the chunks are fine */
static int do_basic_checks(struct nf_conn *ct,
const struct sk_buff *skb,
unsigned int dataoff,
unsigned long *map)
{
u_int32_t offset, count;
sctp_chunkhdr_t _sch, *sch;
int flag;
flag = 0;
for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
pr_debug("Chunk Num: %d Type: %d\n", count, sch->type);
if (sch->type == SCTP_CID_INIT ||
sch->type == SCTP_CID_INIT_ACK ||
sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
flag = 1;
/*
* Cookie Ack/Echo chunks not the first OR
* Init / Init Ack / Shutdown compl chunks not the only chunks
* OR zero-length.
*/
if (((sch->type == SCTP_CID_COOKIE_ACK ||
sch->type == SCTP_CID_COOKIE_ECHO ||
flag) &&
count != 0) || !sch->length) {
pr_debug("Basic checks failed\n");
return 1;
}
if (map)
set_bit(sch->type, map);
}
pr_debug("Basic checks passed\n");
return count == 0;
}
static int sctp_new_state(enum ip_conntrack_dir dir,
enum sctp_conntrack cur_state,
int chunk_type)
{
int i;
pr_debug("Chunk type: %d\n", chunk_type);
switch (chunk_type) {
case SCTP_CID_INIT:
pr_debug("SCTP_CID_INIT\n");
i = 0;
break;
case SCTP_CID_INIT_ACK:
pr_debug("SCTP_CID_INIT_ACK\n");
i = 1;
break;
case SCTP_CID_ABORT:
pr_debug("SCTP_CID_ABORT\n");
i = 2;
break;
case SCTP_CID_SHUTDOWN:
pr_debug("SCTP_CID_SHUTDOWN\n");
i = 3;
break;
case SCTP_CID_SHUTDOWN_ACK:
pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
i = 4;
break;
case SCTP_CID_ERROR:
pr_debug("SCTP_CID_ERROR\n");
i = 5;
break;
case SCTP_CID_COOKIE_ECHO:
pr_debug("SCTP_CID_COOKIE_ECHO\n");
i = 6;
break;
case SCTP_CID_COOKIE_ACK:
pr_debug("SCTP_CID_COOKIE_ACK\n");
i = 7;
break;
case SCTP_CID_SHUTDOWN_COMPLETE:
pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
i = 8;
break;
case SCTP_CID_HEARTBEAT:
pr_debug("SCTP_CID_HEARTBEAT");
i = 9;
break;
case SCTP_CID_HEARTBEAT_ACK:
pr_debug("SCTP_CID_HEARTBEAT_ACK");
i = 10;
break;
default:
/* Other chunks like DATA or SACK do not change the state */
pr_debug("Unknown chunk type, Will stay in %s\n",
sctp_conntrack_names[cur_state]);
return cur_state;
}
pr_debug("dir: %d cur_state: %s chunk_type: %d new_state: %s\n",
dir, sctp_conntrack_names[cur_state], chunk_type,
sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
return sctp_conntracks[dir][i][cur_state];
}
static unsigned int *sctp_get_timeouts(struct net *net)
{
return sctp_pernet(net)->timeouts;
}
/* Returns verdict for packet, or -NF_ACCEPT for invalid. */
static int sctp_packet(struct nf_conn *ct,
const struct sk_buff *skb,
unsigned int dataoff,
enum ip_conntrack_info ctinfo,
u_int8_t pf,
unsigned int hooknum,
unsigned int *timeouts)
{
enum sctp_conntrack new_state, old_state;
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
const struct sctphdr *sh;
struct sctphdr _sctph;
const struct sctp_chunkhdr *sch;
struct sctp_chunkhdr _sch;
u_int32_t offset, count;
unsigned long map[256 / sizeof(unsigned long)] = { 0 };
sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
if (sh == NULL)
goto out;
if (do_basic_checks(ct, skb, dataoff, map) != 0)
goto out;
/* Check the verification tag (Sec 8.5) */
if (!test_bit(SCTP_CID_INIT, map) &&
!test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
!test_bit(SCTP_CID_COOKIE_ECHO, map) &&
!test_bit(SCTP_CID_ABORT, map) &&
!test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
!test_bit(SCTP_CID_HEARTBEAT, map) &&
!test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
sh->vtag != ct->proto.sctp.vtag[dir]) {
pr_debug("Verification tag check failed\n");
goto out;
}
old_state = new_state = SCTP_CONNTRACK_NONE;
spin_lock_bh(&ct->lock);
for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
/* Special cases of Verification tag check (Sec 8.5.1) */
if (sch->type == SCTP_CID_INIT) {
/* Sec 8.5.1 (A) */
if (sh->vtag != 0)
goto out_unlock;
} else if (sch->type == SCTP_CID_ABORT) {
/* Sec 8.5.1 (B) */
if (sh->vtag != ct->proto.sctp.vtag[dir] &&
sh->vtag != ct->proto.sctp.vtag[!dir])
goto out_unlock;
} else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
/* Sec 8.5.1 (C) */
if (sh->vtag != ct->proto.sctp.vtag[dir] &&
sh->vtag != ct->proto.sctp.vtag[!dir] &&
sch->flags & SCTP_CHUNK_FLAG_T)
goto out_unlock;
} else if (sch->type == SCTP_CID_COOKIE_ECHO) {
/* Sec 8.5.1 (D) */
if (sh->vtag != ct->proto.sctp.vtag[dir])
goto out_unlock;
} else if (sch->type == SCTP_CID_HEARTBEAT ||
sch->type == SCTP_CID_HEARTBEAT_ACK) {
if (ct->proto.sctp.vtag[dir] == 0) {
pr_debug("Setting vtag %x for dir %d\n",
sh->vtag, dir);
ct->proto.sctp.vtag[dir] = sh->vtag;
} else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
pr_debug("Verification tag check failed\n");
goto out_unlock;
}
}
old_state = ct->proto.sctp.state;
new_state = sctp_new_state(dir, old_state, sch->type);
/* Invalid */
if (new_state == SCTP_CONNTRACK_MAX) {
pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
"conntrack=%u\n",
dir, sch->type, old_state);
goto out_unlock;
}
/* If it is an INIT or an INIT ACK note down the vtag */
if (sch->type == SCTP_CID_INIT ||
sch->type == SCTP_CID_INIT_ACK) {
sctp_inithdr_t _inithdr, *ih;
ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
sizeof(_inithdr), &_inithdr);
if (ih == NULL)
goto out_unlock;
pr_debug("Setting vtag %x for dir %d\n",
ih->init_tag, !dir);
ct->proto.sctp.vtag[!dir] = ih->init_tag;
}
ct->proto.sctp.state = new_state;
if (old_state != new_state)
nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
}
spin_unlock_bh(&ct->lock);
nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
dir == IP_CT_DIR_REPLY &&
new_state == SCTP_CONNTRACK_ESTABLISHED) {
pr_debug("Setting assured bit\n");
set_bit(IPS_ASSURED_BIT, &ct->status);
nf_conntrack_event_cache(IPCT_ASSURED, ct);
}
return NF_ACCEPT;
out_unlock:
spin_unlock_bh(&ct->lock);
out:
return -NF_ACCEPT;
}
/* Called when a new connection for this protocol found. */
static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
unsigned int dataoff, unsigned int *timeouts)
{
enum sctp_conntrack new_state;
const struct sctphdr *sh;
struct sctphdr _sctph;
const struct sctp_chunkhdr *sch;
struct sctp_chunkhdr _sch;
u_int32_t offset, count;
unsigned long map[256 / sizeof(unsigned long)] = { 0 };
sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
if (sh == NULL)
return false;
if (do_basic_checks(ct, skb, dataoff, map) != 0)
return false;
/* If an OOTB packet has any of these chunks discard (Sec 8.4) */
if (test_bit(SCTP_CID_ABORT, map) ||
test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
test_bit(SCTP_CID_COOKIE_ACK, map))
return false;
memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
new_state = SCTP_CONNTRACK_MAX;
for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
/* Don't need lock here: this conntrack not in circulation yet */
new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
SCTP_CONNTRACK_NONE, sch->type);
/* Invalid: delete conntrack */
if (new_state == SCTP_CONNTRACK_NONE ||
new_state == SCTP_CONNTRACK_MAX) {
pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
return false;
}
/* Copy the vtag into the state info */
if (sch->type == SCTP_CID_INIT) {
if (sh->vtag == 0) {
sctp_inithdr_t _inithdr, *ih;
ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
sizeof(_inithdr), &_inithdr);
if (ih == NULL)
return false;
pr_debug("Setting vtag %x for new conn\n",
ih->init_tag);
ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
ih->init_tag;
} else {
/* Sec 8.5.1 (A) */
return false;
}
} else if (sch->type == SCTP_CID_HEARTBEAT) {
pr_debug("Setting vtag %x for secondary conntrack\n",
sh->vtag);
ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
}
/* If it is a shutdown ack OOTB packet, we expect a return
shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
else {
pr_debug("Setting vtag %x for new conn OOTB\n",
sh->vtag);
ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
}
ct->proto.sctp.state = new_state;
}
return true;
}
static int sctp_error(struct net *net, struct nf_conn *tpl, struct sk_buff *skb,
unsigned int dataoff,
u8 pf, unsigned int hooknum)
{
const struct sctphdr *sh;
struct sctphdr _sctph;
const char *logmsg;
sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
if (!sh) {
logmsg = "nf_ct_sctp: short packet ";
goto out_invalid;
}
if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
skb->ip_summed == CHECKSUM_NONE) {
if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
logmsg = "nf_ct_sctp: bad CRC ";
goto out_invalid;
}
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
return NF_ACCEPT;
out_invalid:
if (LOG_INVALID(net, IPPROTO_SCTP))
nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "%s", logmsg);
return -NF_ACCEPT;
}
static bool sctp_can_early_drop(const struct nf_conn *ct)
{
switch (ct->proto.sctp.state) {
case SCTP_CONNTRACK_SHUTDOWN_SENT:
case SCTP_CONNTRACK_SHUTDOWN_RECD:
case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT:
return true;
default:
break;
}
return false;
}
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
struct nf_conn *ct)
{
struct nlattr *nest_parms;
spin_lock_bh(&ct->lock);
nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
if (!nest_parms)
goto nla_put_failure;
if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
goto nla_put_failure;
spin_unlock_bh(&ct->lock);
nla_nest_end(skb, nest_parms);
return 0;
nla_put_failure:
spin_unlock_bh(&ct->lock);
return -1;
}
static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
[CTA_PROTOINFO_SCTP_STATE] = { .type = NLA_U8 },
[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] = { .type = NLA_U32 },
[CTA_PROTOINFO_SCTP_VTAG_REPLY] = { .type = NLA_U32 },
};
static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
{
struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
int err;
/* updates may not contain the internal protocol info, skip parsing */
if (!attr)
return 0;
err = nla_parse_nested(tb, CTA_PROTOINFO_SCTP_MAX, attr,
sctp_nla_policy, NULL);
if (err < 0)
return err;
if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
!tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
!tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
return -EINVAL;
spin_lock_bh(&ct->lock);
ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
spin_unlock_bh(&ct->lock);
return 0;
}
static int sctp_nlattr_size(void)
{
return nla_total_size(0) /* CTA_PROTOINFO_SCTP */
+ nla_policy_len(sctp_nla_policy, CTA_PROTOINFO_SCTP_MAX + 1);
}
#endif
#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_cttimeout.h>
static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
struct net *net, void *data)
{
unsigned int *timeouts = data;
struct nf_sctp_net *sn = sctp_pernet(net);
int i;
/* set default SCTP timeouts. */
for (i=0; i<SCTP_CONNTRACK_MAX; i++)
timeouts[i] = sn->timeouts[i];
/* there's a 1:1 mapping between attributes and protocol states. */
for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
if (tb[i]) {
timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
}
}
return 0;
}
static int
sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
{
const unsigned int *timeouts = data;
int i;
for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -ENOSPC;
}
static const struct nla_policy
sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
[CTA_TIMEOUT_SCTP_CLOSED] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_COOKIE_WAIT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_COOKIE_ECHOED] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_ESTABLISHED] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_SHUTDOWN_SENT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_SHUTDOWN_RECD] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_HEARTBEAT_SENT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED] = { .type = NLA_U32 },
};
#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
#ifdef CONFIG_SYSCTL
static struct ctl_table sctp_sysctl_table[] = {
{
.procname = "nf_conntrack_sctp_timeout_closed",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_cookie_wait",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_cookie_echoed",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_established",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_shutdown_sent",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_shutdown_recd",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_heartbeat_sent",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "nf_conntrack_sctp_timeout_heartbeat_acked",
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{ }
};
#endif
static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
struct nf_sctp_net *sn)
{
#ifdef CONFIG_SYSCTL
if (pn->ctl_table)
return 0;
pn->ctl_table = kmemdup(sctp_sysctl_table,
sizeof(sctp_sysctl_table),
GFP_KERNEL);
if (!pn->ctl_table)
return -ENOMEM;
pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
pn->ctl_table[7].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_SENT];
pn->ctl_table[8].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_ACKED];
#endif
return 0;
}
static int sctp_init_net(struct net *net, u_int16_t proto)
{
struct nf_sctp_net *sn = sctp_pernet(net);
struct nf_proto_net *pn = &sn->pn;
if (!pn->users) {
int i;
for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
sn->timeouts[i] = sctp_timeouts[i];
}
return sctp_kmemdup_sysctl_table(pn, sn);
}
struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 __read_mostly = {
.l3proto = PF_INET,
.l4proto = IPPROTO_SCTP,
.name = "sctp",
.pkt_to_tuple = sctp_pkt_to_tuple,
.invert_tuple = sctp_invert_tuple,
.print_tuple = sctp_print_tuple,
.print_conntrack = sctp_print_conntrack,
.packet = sctp_packet,
.get_timeouts = sctp_get_timeouts,
.new = sctp_new,
.error = sctp_error,
.can_early_drop = sctp_can_early_drop,
.me = THIS_MODULE,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.to_nlattr = sctp_to_nlattr,
.nlattr_size = sctp_nlattr_size,
.from_nlattr = nlattr_to_sctp,
.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
.nla_policy = nf_ct_port_nla_policy,
#endif
#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
.ctnl_timeout = {
.nlattr_to_obj = sctp_timeout_nlattr_to_obj,
.obj_to_nlattr = sctp_timeout_obj_to_nlattr,
.nlattr_max = CTA_TIMEOUT_SCTP_MAX,
.obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
.nla_policy = sctp_timeout_nla_policy,
},
#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
.init_net = sctp_init_net,
};
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_sctp4);
struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 __read_mostly = {
.l3proto = PF_INET6,
.l4proto = IPPROTO_SCTP,
.name = "sctp",
.pkt_to_tuple = sctp_pkt_to_tuple,
.invert_tuple = sctp_invert_tuple,
.print_tuple = sctp_print_tuple,
.print_conntrack = sctp_print_conntrack,
.packet = sctp_packet,
.get_timeouts = sctp_get_timeouts,
.new = sctp_new,
.error = sctp_error,
.can_early_drop = sctp_can_early_drop,
.me = THIS_MODULE,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.to_nlattr = sctp_to_nlattr,
.nlattr_size = sctp_nlattr_size,
.from_nlattr = nlattr_to_sctp,
.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
.nla_policy = nf_ct_port_nla_policy,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
.ctnl_timeout = {
.nlattr_to_obj = sctp_timeout_nlattr_to_obj,
.obj_to_nlattr = sctp_timeout_obj_to_nlattr,
.nlattr_max = CTA_TIMEOUT_SCTP_MAX,
.obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
.nla_policy = sctp_timeout_nla_policy,
},
#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
#endif
.init_net = sctp_init_net,
};
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_sctp6);
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